Billionaire casino mogul Sheldon Adelson and his wife, Miriam, who have reportedly given a combined $10 million to Winning Our Future, the super PAC that supports and is run by former staffers of Republican presidential candidate Newt Gingrich, were drawn to him by a shared view of the importance of the U.S. relationship to Israel.

But a review of public records by Sunlight suggests that the couple, who appears to be the former House speaker's most generous political patrons pending the filing of Winning Our Future's first complete financial disclosures later this month with the Federal Election Commission, have considerable financial interests involved in battles with the federal government that Gingrich is vying to head:

1. Adelson's company, the Las Vegas Sands, disclosed in its most recent Securities and Exchange Commission quarterly report that it appealed the results of an Internal Revenue Service audit for the company's 2005 to 2008 tax returns. The audit may result in as much as $23 million in additional tax payments, although the final amount, the company concedes, is "inherently uncertain." The IRS also audited Las Vegas Sands' 2009 return, and recommended additional payments. The filings with the SEC do not list the specific issues in the returns. Forbes reports that Las Vegas Sands has "many unusual transactions between the company or its subsidiaries and entities controlled by Mr. Adelson," some of which could have tax implications. 
2. Las Vegas Sands, which has overseas operations in Macau and Singapore, lobbied Congress over regulations affecting "dual capacity taxpayers," essentially, credits claimed against U.S. taxes by companies that make income tax payments to foreign governments for specific benefits–for example, oil companies that pay foreign taxes on the crude they extract. The Obama administration proposed the credit. The U.S. Chamber of Commerce, one of the biggest spenders on lobbying and political influence in the country, seeks to preserve it. 
3. In addition to tax issues, Las Vegas Sands also disclosed in March 2011 that it's the subject of SEC and Justice Department investigations for potentially violating the Foreign Corrupt Practices Act, which bars, among other things, U.S. companies from bribing foreign officials. Las Vegas Sands allegedly put a Chinese official with oversight responsibilities for the company's lucrative Macau operations on its payroll. The company denies wrongdoing and promised to cooperate with the investigation, but notes that "Any determination that we have violated the FCPA could have a material adverse effect on our financial condition."

The U.S. Chamber of Commerce's Institute for Legal Reform has proposed reforms to the Foreign Corrupt Practices Act, claiming that the Justice Dept. and the SEC have become increasingly aggressive in interpreting the law. The Cato Institute has also called for changing the law. 

Adelson, who with his wife owns 57.3 percent of Las Vegas Sands, supports a candidate who, as a member of Congress, had a history of raising issues that benefit his big donors. In 1991, Gingrich vigorously attacked a luxury tax placed on the purchase of yachts; the largest donor to GOPAC, the political organization that Gingrich ran to groom Republican House candidates, was Terry Kohler, whose Windway Capital Corp. owned boat building and nautical supply firms. "As we are all learning–for example, from the boat builders–if you raise taxes on people who buy a product, then you lay off people who are making the product, and it is not very fair to the thousands of boat workers who are not working today." Congress repealed the yacht tax in 1993.

Similarly, the Food and Drug Administration had regulatory authority over several GOPAC donors; as speaker of the House, Gingrich regularly attacked the FDA, and called its administrator, David Kessler, a "thug and a bully," and labeled the FDA "a job killer," according to the Los Angeles Times. Gingrich led an effort to roll back the agency's authority that ultimately failed.